Approval for Remedial Use of the Bottomless Sand Filter (“BSF”)Page 1 of 14

Date of Reissuance: July 17, 2015

Approval for Remedial Use

Bottomless Sand Filter

Residential Design Flows 880 gallons per day (gpd) or less

Authority for Issuance

Pursuant to Title 5 of the State Environmental Code, 310 CMR 15.000, the Department of Environmental Protection (hereinafter “the Department”) hereby issues this Approval for Remedial Use,approving Bottomless Sand Filters (hereinafter “BSF’s”) for use in the Commonwealth of Massachusetts subject to the conditions herein. Design and use of BSF’s are subject to compliance by the Designer, the Installer, the Service Contractor, and the System Owner with the terms and conditions set forth below. Any noncompliance with the terms or conditions of this Approval constitutes a violation of 310 CMR 15.000.

______July 17, 2015

David Ferris, DirectorDate of Reissuance

Wastewater Management Program(Originally issued August 5, 2010)

Bureau of Resource Protection(Revised March 3, 2011, June 26, 2012)

General Description of the Technology

The BSF is an alternative component of a soil absorption system (SAS) for residential on-site sewage disposal systems where soil or site conditions make conventional soil absorption systems more costly to constructor infeasible. A conventional SAS may be more costly to construct or infeasiblewhere there is a shallow water table and/or limited area for the siting of a conventional system. As compared to a conventional system, in certain instances, the BSF provides for higher loading rates and requires significantly less filling of land, less land area, and less disturbance of the site.

The System consists of a BSF preceded by a treatment unit. The treatment unit prior to the BSF must be a unit that is capable of providing secondary treatment and must already be approved by the Department. A specific volume or dose of the treatment unit effluent is periodically pumped at set time intervals to the BSF. The effluent from the treatment unit is pumped onto and evenly distributed over the surface of the BSF. The BSF consists of at least 2 feet of sand media meeting stringent specifications through which the wastewater percolates and is filtered. The bottom of the BSF rests on existing permeable soils or rests on approved fill above existing permeable soils into which the final effluent is discharged for disposal.

The use of a BSF in accordance with this Approval for Remedial Use requires, among other things:

  • Design, installation, and operation of the System generally in accordance with the Rhode Island DEM guidelines upon which the Massachusetts DEP has largely based the Approval and acceptance of this technology in the Commonwealth of Massachusetts;
  • A Designer, Soil Evaluator, and Installer, who have received appropriate training for the design, installation, and use of BSF’s;
  • A MassDEP approved treatment unit prior to the BSF;
  • A Disclosure Notice in the Deed to the property (310 CMR 15.287(10));
  • Certifications by the Designer and the Installer (310 CMR 15.021(3));
  • A Massachusetts certified operator under contract for periodic inspection and maintenance (310 CMR 15.287(10));
  • Periodic sampling, recordkeeping, and reporting, in accordance with this Approval;
  • Notification within 24 hours by the System Owner to the local approving authority of any System failure;
  • 24-hour wastewater storage capacity above the elevation of the high level alarm or back-up power capability in the event power failure; and
  • System Owner Acknowledgement of Responsibilities, in accordance with this Approval.

Definitions and References

The term “System” refers to the BSF in combination with the other components of an on-site treatment and disposal system that may be required to serve a facility in accordance with 310 CMR 15.000.

The term “Approval” refers to this Approval including all Conditions, the General Conditions of 310 CMR 15.287, any Attachments, and the RI DEM referenced documents.

A Deed Notice template is available from the Department.

Relevant RI DEM documents include:

a)RI DEM Soil Evaluation Guidance

b)Rhode Island DEM

Guidelines for the Design, Use, and Maintenance of Pressurized Drainfields

I.Purpose

1.The purpose of this Approval for Remedial Use is to provide conditions under which the local approving authority and Department may approve the use of bottomless sand filters for the upgrade of an existing failed or nonconforming system without an increase in design flow.The facility must meet the specific siting conditions for Remedial Use of an Alternative System (310 CMR 15. 284(2)) and the facility must meet the siting requirements of this Approval.

2.The Approval provides for an allowable reduction in the effective leaching area for residential systems with design flows less than or equal to 880 gpd that employ a BSF designed and approved in accordance with the conditions of this Approval. The effective leaching area reduction is allowable whether or not the BSF is installed in conjunction withan approved Enhanced Nitrogen Removal technology to comply with the Nitrogen Loading Limitation provisions of 310 CMR 15.214.

3.Remedial Use of a Bottomless Sand Filter in Massachusetts may be approved when the design, installation, and operation of the System is in accordance with RI DEM guidelines and complies with the following conditions. To the extent any the following conditions diverge from the RI DEM BSF Guidelines, the conditions of this Approval supplant the RI DEM guidelines.

4.Provided that the local approving authority approves the System in conformance with the Department’s Approval for Remedial Use for the System and the applicant complies with all the conditions of this approval, including submitting all the documentation and certifications as specified herein, Department review and approval of the site-specific System design and installation is not required unless the Department determines on a case-by-case basis, pursuant to its authority at 310 CMR 15.003(2)(e), that the proposed System requires Department review and approval.

5.With the other applicable permits or approvals that may be required by Title 5, the Approval authorizes the installation and use of the Alternative System in Massachusetts. All the provisions of Title 5, including the General Conditions for all Alternative Systems (310 CMR 15.287), apply to the sale, design, installation, and use of the System, except those provisions that specifically have been varied by the Approval.

II.Design and Installation

1.BSF’s shall only be proposed to serve existing facilities for which there is no increase in the actual or proposed design flow and the facilities are served by a failed, failing or nonconforming existing system and where it has been adequately demonstrated to the local approving authority that a connection to a sewer system is infeasible.

When a sanitary sewer connection becomes feasible after a System has been installed, the System Owner shall connect the facility served by the System to the sewer within 60 days of such feasibility and the System shall be abandoned in compliance with current Code requirements, unless a later time is allowed in writing by the Department or the local Approving Authority.

2.The proposed use of a BSF shall be subject to the following:

a)The approved record drawings, on file with the local approving authority, shall clearly indicate an area for the best feasible upgrade without the use of a BSFin the event that the installed BSF System fails or it is determinedthat it is not capable of providing equivalent environmental protection;

b)the installation of the BSF System, including all components, shall not disturb the site in any manner that would preclude the future installation of the best feasible upgrade without the use of a BSF. Components of the installed BSF Systemmay be sited in an areafor the future installation ofthe best feasible upgrade without the use of a BSF, provided that it does not render it unusable for an upgrade; and

a)the System Owner shall not construct any permanent buildings or structures in the area for the best feasible upgrade without the use of a BSF or disturb the site in any manner that would preclude the future installation of the best feasible upgrade without the use of a BSF.

3.When identifying the best feasible upgrade without the use of a BSF, the Designer shall consider these options in the following order:

a)a conventional system designed in accordance with the standards of 310 CMR 15.100 through 15.255 that can be built feasibly, with the exception of providing a reserve area (15.248);

b)a conventional system that can only be built feasibly under a Local Upgrade Approval (LUA);

c)where a conventional system cannot be built feasibly under a LUA, a different Alternative System with Approval for Remedial Use that can be feasibly built;

d)where a System can only be built feasibly with variances, a System that has been demonstrated to vary the design requirements of 310 CMR 15.000 to the least degree necessary and have the least effect on public health, safety, welfare and the environment (the System may be an Alternative System with variances); or

e)a tight tank.

4.Supervision of the installation shall be by the Designer who designed the System and who is a Massachusetts Registered Professional Engineer or Massachusetts Registered Sanitarian and can demonstrate that (s)he has satisfactorily completed 20 hours of appropriate training for the design and installation of BSF’s through the University of Rhode Island (URI) Onsite Wastewater Training Program. Courses OWT 105, OWT 125, and OWT 150 together meet this requirement.

5.A soil suitability assessment shall be performed by a Massachusetts Approved Soil Evaluator in accordance with requirements of Title 5 and RI DEM Soil Evaluation Guidance, except percolation testing is only necessary when required by the local approving authority. The soil suitability assessment shall be recorded on the form approved by the Department and shall include any additional soils information necessary for selection of the allowableloading rate for the BSF.

Additionally, to confirm the field test results for the textural class assigned to the soils, a Particle Size Analysis must be performed. The Particle Size Analysis shall be performed in accordance with MassDEP “Title 5 Alternative to Percolation Testing Guidance for System Upgrades”. (A Particle Size Analysis to confirm the dominant size of the sand fraction may also be performed, if desired.)

6.The allowable loading rate for the design of a BSF shall be based on RI DEM BSF Design Guidelinesand RI DEM Soil Evaluation Guidance. Category 1 Systems Loading Rates may only be used for a System utilizing a time dosed treatment unit prior to the BSF and the treatment unit must be classified by RI DEM as having met the standardsfor Category 1. The treatment unit preceding the BSF must also have Remedial Use Approval granted by MassDEP.

No increase in the BSF loading rates is allowed under LUA.

7.Design flows shall be established in accordance with Title 5 and the System shall only be approved for residential use with a minimum design flow of 330 gpd and a maximum design flow of 880 gpd. The minimum flow may be reduced accordingly if a deed restriction limiting use to 2 bedrooms and 220 gpd is granted to the local Approving Authority or a deed restriction limiting use to 1 bedroom and 110 gpd is granted to the local Approving Authority, as a condition of a variance.

8.In additions to the requirements of this Approval, the Designer, the Installer, the Service Contractor, and System Owner shall be responsible for compliance with the requirements of the Department’s secondary treatment unit Approval.

9.A septic tank meeting the requirements for new construction must precede the secondary treatment unit unless the treatment unit approval does not require it.

10.Except as provided in ParagraphII.11, the BSF must be sited above 4 feet of naturally occurring pervious material.

11.In an area with at least two feet of naturally occurring pervious material, the approving authority may allow a reduction in the required four feet of naturally occurring pervious material layer, only when:

a)it has been demonstrated that the four-foot requirement for naturally occurring pervious material cannot be met anywhere on the site; and

b)no reduction is allowed under LUA for setbacks from public or private wells, bordering vegetated wetlands, surface waters, salt marshes, coastal banks, certified vernal pools, water supply lines, surface water supplies or tributaries to surface water supplies, or drains which discharge to surface water supplies or their tributaries.

12.The local approving authority may grant Local Upgrade Approvals in accordance with the procedures of 310 CMR 15.405, except for the limitations to LUA imposed in ParagraphsII.11 and II.14.

13.To prevent potential sewage breakout, the setback distance from any naturally occurring side slope shall be a minimum of 10 feet measured horizontally in any direction from the bottom of the BSF, provided that the BSF enclosure meets the impervious barrier requirements of 310 CMR 15.255(2) and the Department “Guidelines for the Design and Installation of Impervious Barriers’.

14.The top of the sand of the BSF must be a minimum of 4 feet above seasonal high groundwater, as determined in accordance with Title 5, except in soils with a percolation rate faster than 2 min./inch, where the top of the sand of the BSF must be at least 5 feet above seasonal high groundwater. The approving authority may not allow under LUA a reduction in the required separation between the top of the sand of the BSF and the high groundwater elevation.

15.The depth of sand in the BSF may be increased above the required 2 feet for the purposes of achieving an increased depth to groundwater, provided that the retaining wall supporting the filter sand shall be of suitable structural material and designed by and the construction is supervised by a Massachusetts Registered Professional Engineer.

16.If the bottom of a BSF is above existing grade, the BSF shall be placed on fill meeting the requirements of 310 CMR 15.255(3). Fill may be placed beneath the BSF provided that the horizontal distance of the fill to side slopes shall be 15 feet unless a suitable impervious barrier is installed in the fill, in accordance with the provisions of 310 CMR 15.255(2)and the Department “Guidelines for the Design and Installation of Impervious Barriers’, to prevent potential sewage breakout.

17.Except for septic tank covers which are not required to be at grade, the frames and covers of the access manholes of all System treatment units shall be watertight, made of durable material, and shall be installed and maintained at grade, to allow for necessary operation, sampling and maintenance access. Manholes brought to final grade shall be secured to prevent unauthorized access. No structures which could interfere with performance, access, inspection, pumping, or repair shall be located directly upon or above the access locations.

18.Any treatment unit or other System structures with exterior piping connections located within 12 inches or below the Estimated Seasonal High Groundwater elevation shall have the connections made watertight with neoprene seals or equivalent.

19.The System shall be equipped with sensors and high-level alarms to protect against high water due to pump failure, pump control failure, loss of power, or system freeze up. The control panel including alarms and controls shall be mounted in a location always accessible to the operator (or service contractor). Emergency storage capacity for wastewater above the high level alarm shall be provided equal to the daily design flow of the System and the storage capacity shall include an additional allowance for the volume of all drainage which may flow back into the System when pumping has ceased.

Instead of providing emergency 24-hour storage, an independent standby power source may be provided for operation during an interruption in power. With any interruption of the power supply the source must be capable of automatically activating in addition to manual start up capability. The standby power must be sufficient to handle peak flows for at least 24 hours and sufficient to meet all power needs of the Systemincluding, but not limited to, pumping, ventilation, and controls. Standby power installations must be inspected and exercised at least annually and all automatic and manual start up controls must be tested. Standby power installations must comply with all applicable state and local code requirements. Provided that a standby power installation complies with these requirements, no variance is required to the provisions of 310 CMR 15.231(2).

20.System unit malfunction alarms and high water alarms shall be connected to circuits separate from the circuits to the operating equipment and pumps.

21.All System control units, valve boxes, distribution piping, conveyance lines and other System appurtenances shall be designed and installed to prevent freezing.

22.The Designer shall provide the Approval, an Owner’s Manual and an Operation and Maintenance Manual to the System Owner. The Owner’s Manual and the Operation and Maintenance Manual shall include this Approval and the RI BSF Guideline.

23.The System Owner and the Designer shall not submit to the local Approving Authority a Disposal System Construction Permit (DSCP) application for the use of a Technology under this Approval if the Approval has been revised, reissued, suspended, or revoked by the Department prior to the date of application. The Approval continues in effect until the Department revises, reissues, suspends, or revokes the Approval.